There are many potential triggers, and what triggers a migraine for one might not trigger it in another. However, here are several of the most commonly reported triggers:
Food and Drink: Many people experience migraines when they eat certain foods, especially wheat, dairy, sugar, artificial preservatives or chemical additives. Cured or processed meats, alcohol, aspartame, caffeine, and MSG are common culprits.
Allergies: Including food allergies and food sensitivities, and chemical sensitivities.
Dehydration and/or Hunger
Changes in sleeping cycle: Both missing sleep and oversleeping can trigger a migraine.
Stress: Any kind of emotional trauma can trigger a migraine, even after the stress has passed.
Physical exertion: Extremely intense exercise or even sex has been known to bring on migraines.
Hormones: Some women experience migraines before, or during their periods, during pregnancy, or during menopause. Others may get migraines from hormonal medications like birth control pills, or hormone replacement therapy.
External stimuli: Bright lights, fluorescent lights, loud noises and strong smells (even pleasant ones) can trigger a migraine.
Weather changes, Seasonal changes, and changes in Altitude